Acorus calamus, commonly known as sweet flag or calamus ( Sanskrit : Haimavati, हैमवती, Vacha, वचा ) and various rushes and sedges,[1] is a plant from the Acoraceae family, in the genus Acorus. It is a tall perennial wetland monocot with scented leaves and more strongly scented rhizomes, which have been used medicinally, for its odor, and as an allegedly psychotropic drug. Its Sanskrit name is vacha.[2] Probably indigenous to India, Acorus calamus is now found across Europe, in southern Russia, northern Asia Minor, southern Siberia, China, Indonesia, Japan, Burma, Sri Lanka, Australia, as well as southern Canada and Northern USA (which are diploid Acorus americanus). Indigenous diploid plants in northern Asia may be part of A. americanus.[3]

Botanical information

The morphological distinction between the Acorus species is made by the number of prominent leaf veins. Acorus calamus has a single prominent midvein and then on both sides slightly raised secondary veins (with a diameter less than half the midvein) and many fine tertiary veins. This makes it clearly distinct from Acorus americanus.

The leaves are between 0.7 and 1.7 cm wide, with average of 1 cm. The sympodial leaf of Acorus calamus is somewhat shorter than the vegetative leaves. The margin is curly-edged or undulate. The spadix, at the time of expansion, can reach a length between 4.9 and 8.9 cm (longer than A. americanus). The flowers are longer too, between 3 and 4 mm. Acorus calamus is infertile and shows an abortive ovary with a shriveled appearance.

Acorus americanus was formerly classified as Acorus calamus var. americanus. The species name, "americanus" simply indicates that this is an American species of Acorus. It differs only in being a fertile diploid (2n = 24)], whereas most of the A. calamus of Europe and Asia is a sterile triploid species, that only spreads asexually. Diploid plants in northern Asia may be part of A. americanus.[4]Also as a diploid it does not produce b-asarone.

Both triploid and tetraploid calamus contain asarone. Other phytochemicals include:

* Beta-asarone [5], [6], [7], [8]

Diploids do not contain beta-asarone (β-asarone).[9]

Regulations

Calamus and products derived from calamus (such as its oil) were banned in 1968 as food additives and medicines by the United States Food and Drug Administration.[10]This ban was the result of lab studies that involved supplementing the diets of lab animals over a prolonged period of time with massive doses of isolated chemicals (β-asarone) from the Indian Jammu strain of calamus. The animals developed tumors, and the plant was labeled procarcinogenic.[11][12]Wichtl says “It is not clear whether the observed carcinogenic effects in rats are relevant to the human organism.”[13]However, most sources advise caution in ingesting strains other than the diploid strain.

Four varieties of Acorus calamus strains exist in nature; diploid, triploid, tetraploid and hexaploid. [14] Diploids do not produce the procarcinogenic β-asarone. Diploids are known to grow naturally in Eastern Asia (Mongolia and C Siberia) and North America. The triploid cytotype probably originated in the Himalayan region, as a hybrid between the diploid and tetraploid cytotypes. [15] The North American Calamus is known as Acorus Calamus var. Americanus or more recently as simply Acorus Americanus. Like the diploid strains of calamus in parts of the Himalayas, Mongolia, and C Siberia, the North American diploid strain does not contain the procarcinogenic β-asarone.[16][17][18] Research has consistently demonstrated that “β-asarone was not detectable in the North American spontaneous diploid Acorus [Calamus var. Americanus]”.[19]

In reality β-asarone is not actually a carcinogen but it is a procarcinogen that is neither hepatotoxic nor directly hepatocarcinogenic. It must first undergo metabolic l'-hydroxylation in the liver before achieving toxicity. Cyrochrome P450 in the hepatocytes is responsible for secreting the hydrolyzing enzymes that convert β-asarone into genotoxic epoxide structure. [20] We are told that even with activation of these metabolites, the carcinogenic potency is very low due to the rapid breakdown of epoxide residues with hydrolase which leaves these compounds inert (Luo, 1992). Additionally, the major metabolite of β-asarone is 2,4,5-trimethoxyninnamic acid, a derivative which is not a carcinogen (Hasheminejad & Caldwell, 1999). Again, we are still cautioned about ingesting any calamus derivatives outside of the diploid strain.

Uses

Calamus has been an item of trade in many cultures for thousands of years. Calamus has been used medicinally for a wide variety of ailments, and its smell makes calamus essential oil valued in the perfume industry.

In antiquity in the Orient and Egypt, the rhizome was thought to be a powerful aphrodisiac. In Europe Acorus calamus was often added to wine, and the root is also one of the possible ingredients of absinthe. Among the northern Native Americans, it is used both medicinally and as a stimulant. It is believed by some that calamus is an hallucinogen. This urban legend is based solely on two pages of a book written by Hoffer and Osmund entitled The Hallucinogens. The information on these two pages came from anecdotal reports from two individuals (a husband and wife) who reported that they had ingested calamus on a few occasions.[21][22] None of the components in calamus are converted to TMA (trimethoxyamphetamine) in the human organism.[22] To date there is no solid evidence of any hallucinogenic substances in calamus. Acorus calamus shows neuroprotective effect against stroke and chemically induced neurodegeneration in rat. Specifically, it has protective effect against acrylamide induced neurotoxicity.[23]

Cultural uses

For the Penobscot people this is a very important root. One story[citation needed] goes that a sickness was plaguing the people. A muskrat spirit came to a man in dream and told him that he was a root. He told the man where to find him. The man awoke, found the root, and made a medicine which cured the people. In Penobscot homes, the root was cut and hung up. Steaming it throughout the home is thought to cure sickness. While traveling, a piece of root was kept and chewed to ward off illness.

Teton-Dakota warriors chewed the root to a paste, which they rubbed on their faces. It prevented excitement and fear when facing an enemy.

The Ojibway make a tea by taking a piece of root and scalding it, then drinking the tea warm. Gargling the tea or chewing on a piece of root is also good for sore throat.

The Potawatomi people powder the dried root and put this up the nose to cure a runny nose.

Herbal medicine

Sweet flag has a very long history of medicinal use in many herbal traditions.[citation needed] It is widely employed in modern herbal medicine as an aromatic stimulant and mild tonic. In Ayurveda it is highly valued as for its ability to bring clarity to the consciousness. It is the best remedy for the ill effects of alcohol, particularly on the brain and liver, and is used in Ayurveda to counter the side effects of all hallucinogens. {[24]|date=April 2010} This root has been used as a rejuvenator for the brain and nervous system and as a remedy for digestive disorders. However, some care should be taken in its use since some forms of the plant might be carcinogenic[citation needed] . The root is anodyne, aphrodisiac, aromatic, carminative, diaphoretic, emmenagogue, expectorant, febrifuge, hypotensive, sedative, stimulant, stomachic, mildly tonic and vermifuge. It is used internally in the treatment of digestive complaints, bronchitis, sinusitis etc.

It is said to have wonderfully tonic powers[citation needed] of stimulating and normalizing the appetite. In small doses it reduces stomach acidity whilst larger doses increase stomach secretions and it is, therefore, recommended in the treatment of anorexia nervosa. However if the dose is too large it will cause nausea and vomiting. Sweet flag is also used externally to treat skin eruptions, rheumatic pains and neuralgia. An infusion of the root can bring about an abortion whilst chewing the root alleviates toothache. It is a folk remedy for arthritis, cancer, convulsions, diarrhoea, dyspepsia, epilepsy etc. Chewing the root is said[who?] to kill the taste for tobacco. Roots 2 – 3 years old are used since older roots tend to become tough and hollow. They are harvested in late autumn or early spring and are dried for later use. The dry root loses 70% of its weight, but has an improved smell and taste. It does, however, deteriorate if stored for too long. Caution is advised on the use of this root, especially in the form of the distilled essential oil, since large doses can cause mild hallucinations. A homeopathic remedy is made from the roots to be used in the treatment of flatulence, dyspepsia, anorexia and disorders of the gall bladder.

Cultural symbolism

The calamus has long been a symbol of love. The name is associated with a Greek myth: Kalamos, son of the river-god Maeander, who loved the youth Karpos, of Zephyrus (the West Wind) and Chloris (Spring). When Karpos drowned in a swimming race, Kalamos also drowned and was transformed into a reed, whose rustling in the wind was interpreted as a sigh of lamentation.

The plant was a favorite of Henry David Thoreau (who called it "sweet flag"), and also of Walt Whitman, who added a section called the "Calamus" poems, to the third edition of Leaves of Grass (1860). In the poems the calamus is used as a symbol of love, lust, and affection.

The name Sweet Flag refers to its sweet scent (it has been used as a strewing herb) and the wavy edges of the leaves which are supposed to resemble a fluttering flag.
Etymology of calamus

Cognates of the Latin word calamus are found in both Greek (kalamos, meaning "reed") and Sanskrit (kalama, meaning "reed" and "pen" as well as a sort of rice) — strong evidence that the word is older than all three languages and exists in their parent language, Proto-Indo European. The Arabic word qalam (meaning "pen") is likely to have been borrowed from one of these languages in antiquity, or directly from Indo-European itself.

From the Latin root "calamus", a number of modern English words arise:

* calamari, meaning "squid", via the Latin calamarium, "ink horn" or "pen case", as reeds were then used as writing implements;
* calumet, another name for the Native American peace pipe, which was often made from a hollow reed;
* shawm, a medieval oboe-like instrument (whose sound is produced by a vibrating reed mouthpiece);
* chalumeau register, the lower notes of a clarinet's range (another reed instrument).